Using the pitch control system for illustration, the pilot may have a control by which he transmits power assisted torque through right and left subsystems to the right and left pitch control surfaces of the wing. It may occur that one or the other of the surfaces or its corresponding subsystem becomes damaged or jammed. Ordinarily, if one is jammed, the other is bound also. Normally locked disconnect devices have been proposed for incorporation in the actuating subsystems for the right and left control surfaces, adapted, when operated, to disconnect the jammed side, and free the balance of the overall control system for unhindered operation. The airplane may ordinarily be flown in such a partially disabled condition.